Cyclone discharge chamber



Nov. 17, 1959 c. R. HusToN. Erm. I

Filed Nov. s, 1955 United States Patent O CYCLONE DISCHARGE CHAMBER Charles R. Huston, Algonquin, Ill., and Grant H. Hartman, Manitowoc, Wis., assignors to Cherry-Burrell Corporation, Chicago, Ill., a corporation of Delaware Application November 8, 1955, Serial No. 545,753

' s claims. (c1. :s4- 57) Our invention relates to a method of and means for discharging tacky granules, such as moistened and agglomerated milk particles, from a cyclone type collector or the like, into a drying duct, and has reference more particularly to a valveless communicating chamber adapted to be interposed between a collector and a duct in place of the commonly used types of valves such as rotary or flapper valves.

This type of communicating means is applicable to systems of the type disclosed in copending application Serial No. 479,402, led January 3, 1955, by Grant H. Hartman, Henry F. Harder, Albin I. Rezba, and Robert K. Reeve for Dispersible Dried Milk. In such systems, dry milk powder such as non-fat dry milk solids are introduced into a moistening tube through which moist air is passed, the powder` being moistened therein and conveyed thereby to a cyclone type collector. In their `moistened condition, the powder particles become tacky and tend to cling together in clusters. From the collector, the tacky clusters pass through a valve to a drying tube through which warm, dry air is moving. Such clusters have a tendency, because of their tackiness, to adhere upon contact to the interior walls and parts of the valve.

It is a principal object of our invention to provide means interposable between the discharge of a cyclone type collector and the inlet of a duct or the like adapted to ycontrol communication therebetween and to eliminate the tendency to clog which occurs with conventional valves when particles are passed therethrough.

rvIt is another object of our invention to design such means which afford a preliminary drying action for moistened particles passing therethrough from a cyclone collector to a drying duct.

It is a further object of our invention to prevent moist air from entering the drying tube or duct by providing means whereby a controlled amount of warm, dry air. from the drying tube may be exhausted therefrom concurrent with the introduction of moist particles into said drying tube.

v-And it is a still further object of our invention to devise a method and facilities which are simple and eilicient for the handling of particles, and particularly moistened particles passing from a cyclone collector to a duct or the like, such as a drying duct, these and other objects being accomplished as hereinafter described, reference being had to the accompanying drawing in which Fig. l is a side view of a milk powder moistening and, drying system with a discharge chamber embodying our invention interposed between the moistening and drying portions thereof; and

Fig. 2 is a sectional view of the discharge chamber of Fig. l showing portions of the adjoining moistening and drying facilities.

Referring now to the drawing, the discharge chamber embodying our invention is indicated generally by the reference' numeral 10 and is interposed between va cyclone type collector 11 and a drying duct 2S as shown in Fig. 1.

The collector 11 is located at one end of a moistening tube or duct 12, and a blower 13-preferably of the centrifugal typeis mounted at the other end of said moistening duct 12. A return duct 14 is provided from the top of the cyclone collector 11 back to the blower 13 and said return duct 14 communicates with the inlet of the blower 13. A steam pipe 15 is connected at any desired location to the casing of the blower 13 so as to permit supplying of steam to the moistening duct 12.

In order to regulate the quantity of steam supplied to the blower 13 and thus to the duct 12, the steam pipe 15 is provided with a valve 16 which may be adjusted to varying positions as desired.

A hopper 17 is mounted near the blower 13 end of the moistening tube 12 and communicates with said'tube 12 through a feed pipe 18. Dry milk powder or other product to be processed is fed from the hopper 17 to the moistening tube 12, and in order to insure positive delivery thereof at a predetermined rate, a mechanically driven screw feed (not shown) may be installed in the feed pipe 18.

It will be understood that the blower 13, the moistening duct 12, the collector 11, and the return duct 14 comprise a substantially closed air recirculating system, the only outlet therefrom being a product discharge throat 19 at the base of the collector 11, said throat 19 being adapted to permit particles carried to said collector 11 by the airstream through the moistening duct 12 to fall free from said collector 11.

The product discharge throat 19 of the cyclone collector 11 is enclosed by a communicating chamber 16. Said communicating chamber 10 comprises a cylindrical upper portion 20 and a depending funnel-like conical portion4 21 with a neck 22 therebelow. The chamber 10 is provided with a cover 23 which is adapted to shield the top of said chamber 10 but to permit lateral air escape therefrom. As shown in Fig. 2, the cover 23 may be of larger diameter than the cylindrical upper portion 20 and may be of inverted dish-like form with a hole through the center to receive the product discharge throat 19 of the cyclone collector 11. The cover 23 is provided on its underside with integral radial ribs 24 or the like adapted to rest on the top edge of the upper portion 20 of the chamber 10 and thereby to support the cover 23 in a is provided with 'an air inlet duct 2S communicating with' the suction side of said blower 27, the air inlet .duct 28 having a damper 29 therein so as to permit regulation vof the volume of air introduced into said blower 27.

The other end of the drying duct 25 may have an upturned section 30 with an end thereof turned horizontally and leading tangentially into a cyclone collector 31. The

cyclone collector 31 has an air discharge duct 32 counected centrally to the top of said cyclone collector 31 and communicating at the other end to the suction side of a blower 33. A damper 34 is provided in the air outlet duct 32 between the collector 31 and the blower 33 to permit control of the relative volume ofmair discharged from the cyclone collector 31. If preferred, the damper may, of course, be provided at the outlet of the blower 33.

The various components of the system as disclosed in the drawing are designed for convenient disassembly and reassembly so as to permit frequent cleaning. They y should be-made of material suitable for handling the product to be processed. In the case of milk, for example,

Patented i N ov. 1 7, y1 959 A n ne it spreferable to use a material that is not harmful thereto, such as stainless steel and certain types of plastic material.

1n operation the blowers 13 and 27 are started and the heater 26 is turned on. The system is permitted to operate in this manner as part of the startup procedure so as to cause air heated by the heater 26 to be forced upwardly through the communicating chamber and through the product discharge throat 19 and the cyclone collector 11. The circulation of air by the blower 13 through the moistening duct 12 into the cyclone collector 11 and back through the return duct 14 permits introduction of warmed air from the collector 11 into the ducts 12 and 14, thereby warming them sufficiently for optimum operation.

When a desired operating temperature is achieved in the ducts 12 and 14, the blower 33 is started and the dampers 34 and 29 are adjusted so that at least an equal and, if desired, a greater volume of air is introduced through the air intake 28 to the blower 27 than is discharged through the blower 33. This serves to maintain the air pressure in the drying duct at an equal or greater pressure than that in the collector 11 and thus prevents escape of moist air from said collector 11 into the drying duct 25 where it would impair the drying eff-iciency of the air passing therethrough. When a greater pressure is maintained in the drying duct 25 than in the collector 11 some warm air is discharged upwardly from said drying duct 25 through the neck 22 into the communicating chamber 10, thus maintaining a constant flow of relatively warm dry air into the communicating chamber 10 and outwardly therefrom to the atmosphere.

Because of the relatively closed character of the air circulation through the moistening duct 12, the collector 11, the return duct 14, and the blower 13, substantially uniform atmospheric pressure is maintained at the discharge throat 19 of the collector 11. Thus, since the communicating chamber 10 is likewise at the atmospheric pressure because of the air spaces between the cover 23 and the top edge of the upper portion 2G of the communicating chamber 1t), air flowing from the drying duct 25 into the communicating chamber 10 tends to pass outwardly therefrom as indicated by the arrows in Fig. 2.

It is desirable that the flow of air upwardly through the communicating chamber 1t) be at low velocity so that when powder is introduced into said communicating chamber 10 from the discharge throat 19, it will not be carried by such air out into the atmosphere.

When the system is operating with the desired balance of air ows, particles of dry milk powder or other product to be processed in the system may be introduced into the moistening duct 12 and at the same time the steam valve 16 is opened to introduce steam into the blower 13. The effect of the introduction of steam into the blower 13 is to moisten the air circulating from the blower 13 through the moistening duct 12 and as particles of product, such as dry milk powder, are carried by the air ow through the moistening duct 12 some of the moisture in the air is absorbed by the particles passing through said moistening duct 12 and there is a tendency for the particles to become tacky and to cluster somewhat because ofthe moistening occurring in the duct 12. lt is to be understood that the amount of moisture introduced into the air ow through the moistening duct 12 may be regulated by adjustment of the steam valve 16.

The moist particles or clusters enter the cyclone collector 11 relatively tangentially from the moistening duct 12 and tend by gravity and centrifugal force to become separated from the air stream from the moistening tube 12 and to drop to the bottom of the collector 11 and through the discharge throat 19 into the communicating chamber 10.

The gentle ow of warm, dry air upwardly through the communicating chamber l@ tends to cause preliminary and partial drying of the moistened particles or clusters as they pass from the discharge throat 19 to theneclt 22 of the communicating chamber 10 and into the drying duct 25. The slight excess of air pressure in the drying duct 25 and the constant upflow of warm, dry air therefrom through the communicating chamber 10 prevents any moist air which may be discharged through the throat 19 from entering the drying duct 25.

The particles or clusters dried in the ow of warm air through the drying duct 25 are introduced into the collector 31 with the stream of air from the upturned section 3f! of the drying duct 25 and at that point are separated from the air, the air passing outwardly from the collector 31 through the duct 32 and the particles or clusters dropping to the bottom ofthe collector 31, from which point they may be conveyed through processing or packaging steps which are not a part of the present invention.

We have shown and described our communicating chamber invention in a preferred form and in combination with a system in which it has particular activity. it is to be understood, however, that modification may be made in the form of the communicating chamber and in the means provided in the system with which it is` used for controlling and balancing air flow and pressure. Such modification may be made without departing from the spirit of our invention, the scope of which is to be determined by the appended claims.

We claim:

l. A communicating chamber of the class described.

adapted to be interposed between two ducts, said charnber comprising the combination of a relatively funnelshaped housing and a cover therefor, said housing having a top portion of relatively broad cross-section, an inwardly tapering midsection, and a depending neck therebelow adapted to communicate with one of said ducts, and said cover being of inverted relatively dished-out form, of greater breadth than said top portion and removably engaged thereon, said cover having a central opening to. receive the other of said ducts and having,

supporting ribs in the dished-out side to support said cover on said top portion at a predetermined level to permit air communication to the outside.

2. In combination, a relatively funnel-shaped casing having a discharge throat at its lower end to discharge solids downwardly therefrom, a second funnel-shaped casing disposed in substantially axial relation therebelow and having a discharge throat at its lower end, an air duct disposed below and adapted to communicate with the discharge throat of said second casing, and a removable lid for said second casing, said lid having a central.

opening in which the discharge throat of the first casing is received when the lid is in place on the second casing,

and means mounting said lid in spaced relation to said.

second casing, said means further defining exhaust ports for said. second casing.

3. The combination of a funnel-shaped casinghaving a. discharge throat at its lower end to discharge solids downf wardly therefrom, a second funnel-shaped casing disposed therebelow in partially telescoped axial relation,

with said throat, and a horizontal duct disposed below and having a lateral port connected to and proving free` communication with said second casing, said second casing having thereon a removable lid with a central openingl which receives said discharge throat, Said lidbeing provided on the side adapted to engage the second casing,`

with a lateral rib adapted to support said lid a predetermined distance above said second casing to permit air ow therebetween.

4. The combination of a funnel-shaped casing havingA a discharge throat at its lower. end to discharge solids downwardly therefrom, a second funnel-shaped casingl disposed therebelow in partially telescoped axial relation with said throat, and a horizontal duct disposed below and having a lateral port connected to and providing free.

communication with said secondv casing, said secondv .fin

casing having thereon a removable lid with a centra] opening which receives said discharge throat, and means adapted to support said lid a predetermined distance above said second casing, said means further dening exhaust ports for said second casing.

5. In combination, a cyclone collector having a discharge opening at its lower end, a substantially cycloneshaped casing defining a chamber of smaller volume than said collector and having a discharge opening at its lower end, the upper end of said casing communicating 10 with the discharge opening of said collector, an air duct disposed below and adapted to communicate with the discharge opening of said casing, a cover adapted to be disposed on the upper end of said casing and encircling the discharge opening of said collector, and means supporting said cover a selected distance above the upper end of said casing while providing for communication between said chamber and the exterior of said casing.

References Cited in the le of this patent UNITED STATES PATENTS 1,892,233 Chappell Dec. 17, 1932 2,316,207 Winter Apr. 13, 1943 2,335,732 Bowen Nov. 30, 1943 

